North American Fruit Explorers mailing list at ibiblio

[Lon Rombough <lonrom@hevanet.com>]

There is also a Pyrus x Cydonia,  aka Pyronia, which is a "graft hybrid" of pear and quince.  The theory is that in very rare cases, tissues of the stock and scion are in contact in such a way that cells fuse to make a sort of physical (as opposed to sexual) hybrid of the two species, AND the fused cells are in the right place to grow into a shoot that shows the traits of both "parents".  Apparently there were serious research attempts to cause such hybrids to form these "graft hybrids" by grafting plants, then cutting them off at the union in an attempt to force hybrid shoots from the callus union.
I have the Crataegomespilus hybrid (or one such) and it does show traits of both hawthorn and medlar.
-Lon Rombough
Grapes, writing, consulting, my book, The Grape Grower, at http://www.bunchgrapes.com  Winner of the Garden Writers Association "Best Talent in Writing" award for 2003.
On Feb 16, 2005, at 6:02 PM, John Smith wrote:

I was pondering Stephen Sadler's information and
looking some things up, when I discovered there is
apparently a +Crataegomespilus which is a hybrid
between hawthorn and a medlar that was created by
grafting, not hybrid created by a sexual cross.  I had
no idea a graft could take on characteristics of both
parents...  I always thought the scion would maintain
it's separate genetics, but I guess that's not always
the case.  I wonder how common this is?